The ROC analysis presented here was performed on the data including all groups (22q, CR, ZR, NC). Groups status was coded as “22q” or “not22q”.
Sample sizes:
| 22q | CR | NC | SZ |
|---|---|---|---|
| 168 | 19 | 97 | 41 |
ROC curve with optimal cut-off point (Specificity, Sensitivity). Optimal cut-off is defined as the point that maximizes Youden’s index defined as \(J = sensitivity + specificity − 1\)
## Area under the curve: 0.8845
## 95% CI: 0.8495-0.9195 (DeLong)
PCA was performed without scaling gestalt scores (covariance PCA).
Needs work.
## Area under the curve: 0.9046
## 95% CI: 0.873-0.9361 (DeLong)
##
## DeLong's test for two correlated ROC curves
##
## data: resROC and resROC_PCA
## Z = -2.7122, p-value = 0.006684
## alternative hypothesis: true difference in AUC is not equal to 0
## sample estimates:
## AUC of roc1 AUC of roc2
## 0.8845352 0.9045723
A weighted combination of syndrome scores improves the AUC relative to predicting 22q status based on only 22q syndrome scores.
## Area under the curve: 0.6753
## 95% CI: 0.5894-0.7611 (DeLong)
##
## Welch Two Sample t-test
##
## data: NC_score and SZ_score
## t = 3.7495, df = 83.679, p-value = 0.0003253
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
## 0.07023095 0.22887998
## sample estimates:
## mean of x mean of y
## 0.13597450 -0.01358097
## Cohen's d | 95% CI
## ------------------------
## 0.67 | [0.29, 1.04]
##
## - Estimated using pooled SD.
##
## Welch Two Sample t-test
##
## data: NC_score and CR_score
## t = 3.8668, df = 33.034, p-value = 0.0004897
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
## 0.08249714 0.26569048
## sample estimates:
## mean of x mean of y
## 0.13597450 -0.03811931
## Cohen's d | 95% CI
## ------------------------
## 0.78 | [0.28, 1.28]
##
## - Estimated using pooled SD.
##
## Welch Two Sample t-test
##
## data: SZ_score and CR_score
## t = 0.48897, df = 42.756, p-value = 0.6274
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
## -0.07668375 0.12576044
## sample estimates:
## mean of x mean of y
## -0.01358097 -0.03811931
## Cohen's d | 95% CI
## -------------------------
## 0.13 | [-0.42, 0.67]
##
## - Estimated using pooled SD.